Simplified silk screen printing device

ABSTRACT

A silk screen printing machine comprises a base plate upon which a silk screen frame is pivotally mounted by means of a &#39;&#39;&#39;&#39;living hinge&#39;&#39;&#39;&#39; in the form of a transparent polypropylene sheet. The frame is pivotable between a printing position where it lies flat upon the base to a ready position where it is positioned away from the base. The transparent polypropylene sheet extends across the base in line with the frame opening. This permits a proof impression from the silk screen to be placed on the transparent sheet. A blank of the material to be imprinted is positioned under the transparent sheet for the purpose of registering the imprint. Then a guide tape outlining the blank is placed on top of the transparent sheet as a guide for subsequent placement of blanks on the transparent sheet. A porous cellular element receives ink and is guided for movement along the silk screen to force ink through the screen to the blank sheets of material to be imprinted.

United States Patent 1 1 Neman Dec. 16, 1975 1 1 SIMPLIFIED SILK SCREEN PRINTING DEVICE [76] Inventor: Mary Neman, 2531 Vera Ave.,

Cincinnati, Ohio 45237 [22] Filed: Aug. 6, 1973 [21] Appl. N0.: 385,737

[56] References Cited UNITED STATES PATENTS 1,568,651 l/1926 Bryson 101/114 X 1,938,904 12/1933 Harris 101/114 UX 2,542,059 2/1951 Roscn 101/123 2,704,511) 3/1955 Walsh, Jr. 101/123 2,739,530 3/1956 McLaurin 101/123 2,976,560 3/1961 Turner .1 15/244 R X 2,977,619 4/1961 Franzenc 15/244 R X FOREIGN PATENTS OR APPLICATIONS 633,347 7/1936 Germany 101/123 Primary ExaminerEdgar S, Burr Assistant ExaminerR. E. Suter Attorney, Agent, or Firm1rwin P. Garfinkle [57] ABSTRACT A silk screen printing machine comprises a base plate upon which a silk screen frame is pivotally mounted by means of a living hinge" in the form of a transparent polypropylene sheet. The frame is pivotable between a printing position where it lies flat upon the base to a ready position where it is positioned away from the base. The transparent polypropylene sheet extends across the base in line with the frame opening. This permits a proof impression from the silk screen to be placed on the transparent sheet. A blank of the material to be imprinted is positioned under the transparent sheet for the purpose of registering the imprint. Then a guide tape outlining the blank is placed on top of the transparent sheet as a guide for subsequent placement of blanks on the transparent sheet. A porous cellular element receives ink and is guided for movement along the silk screen to force ink through the screen to the blank sheets of material to be imprinted.

14 Claims, 5 Drawing Figures US. Patent Dec. 16, 1975 Sheet10f2 3,926,112

U.S. Patent Dec. 16,1975 Sheet20f2 3,926,112

SIMPLIFIED SILK SCREEN PRINTING DEVICE Silk screen printing machines and processes are an economical and effective way of printing images on blank sheet material. The conventional machine comprises a screen that is imperforate except in those areas conforming to an imprint to be transferred. Generally, the screen is held in a frame which is displaceablc against a base upon which a blank material has been placed. Ink or other printing liquid is poured into the frame and over the upper face of the screen. A squeegee, swept across the screen, forces the ink through the porous areas to produce an imprint on the blank material.

Several problems are involved in the use of this type of device. One of them is the registration of the blanks with the screen. In most cases proper alignment of the diverse sizes of blank sheets with the many different patterns that may be placed on the silk screen, requires a mechanical registration device or time-consuming trial and error methods.

Another problem with prior art printing machines arises from the manner in which ink is poured on the silk screen in the frame. The large quantity of ink in the frame makes it necessary to provide a means to prevent spillage of the ink when the frame is pivoted from the printing position. This generally necessitates a mechanism to position the frame between the printing and ready position while maintaining it in a generally horizontal position. Also, the large quantity of ink is messy and requires a difficult clean-up procedure.

The registration problem is solved in one aspect of the invention by the use of an extended transparent living hinge" between the base and the frame. The living hinge" is a transparent sheet which pivotally connects the frame to the base and which extends over the base so that a proof imprint can be made on it. A blank placed under the transparent sheet can then be quickly registered with the proof imprint, on the transparent sheet, and a suitable guide may then be applied to the sheet.

Another of the above problems is solved by the use of a porous spongelike squeegee element for storing the supply of ink, and in addition providing the means for driving the ink through the screen onto a blank sheet.

The above and other related features of the present invention will be apparent from a reading of the following description along the accompanying drawings in which:

FIG. 1 is a plan view of a printing device embodying the present invention;

FIG. 2 is a side elevational view of the printing device of FIG. 1 shown in a printing position;

FIG. 3 is a side elevational view of the printing device of FIG. 1 shown in a ready position;

FIG. 4 is a greatly enlarged fragmentary section view taken on line 4-4 of FIG. 1; and

FIG. 5 is a view taken on line 5-5 of FIG. 4.

FIGS. 1 and 2 show a generally rectangular printing base plate 10. A frame 12 is pivotally mounted to base along an edge 14. An elongated plate 17 is secured to the edge 14 of frame 12. An elongated thin resilient sheet forms a hinge 18 (preferably polypropylene) secured to plate 17 by screws 16 and 19. Alternately, hinge 18 may be secured directly to frame 12. Hinge 18 is secured to base 10 along edge 14 of frame 12 by screws 20. The hinge 18 is commonly known as a living" hinge and this term, as used herein, is intended to apply to a sheet material having good elastic or spring qualities. The undcformed shape of hinge I8 is flat so that it resiliently biases frame l2 upward from the printing" position lying flat on base l0 (FIG. I) to the raised ready position (FIG. 3). A bumper, comprising an upright post 23 and a resilient sleeve 2l, forms a stop for the frame l2 in its ready" position.

Frame l2 has an opening 24 which is adapted to receive a screen printing frame 26 supporting a porous screen 28 (shown in one form as a silk screen). A thin sheet 29 is affixed to the bottom of frame 12 and has an opening 31 smaller than opening 24 to hold the screen frame 26 in place (see FIG. 4). A transparent sheet 22 extends from living" hinge l8 across the base 10 so that the sheet 22 extends beyond the limits of opening 24 when frame I2 is in its printing position. Preferably, sheet 22 is integral with hinge 18.

A first set of guide rails 30 is secured to posts 32 mounted on frame 12. A second set of guide rails 34 is connected to posts 36, also mounted on frame 12. The first and second sets of guide rails 30, 34 are generally parallel to one another and to opposite edges of the opening 24. A pair of flexible plastic clips 38 and 40 have hooked ends 42 and 44, respectively, which snap over guide rails 30 and 34, respectively (see FIG. 4). This permits the clips to move only in a direction parallel to the longitudinal axis of the rails 30 and 34. A shaft 46 extending across opening 24 has tapered ends 48 received in holes 50 and 52 of clips 38 and 40, respectively.

Shaft 46, as shown in FIGS. 4 and 5 particularly, extends through an elongated slot 54 in an operatormanipulated handle 56. A semi-cylindrical base 58 has an elongated tab 60 which is suitably releasably received in the elongated slot 54. A pair of sleeves 55, telescoped over the ends of shaft 46, helps center the handle 56 over opening 24.

A porous ink-retaining element 62 is secured to the outer surface of the cylindrical base 58. Preferably, this element is made from a flexible porous cellular material that can readily absorb and retain ink. As shown in FIG. 1, the clips 38 and 40 and guide rails 30, 34 guide the movement of the porous ink-retaining element 62 in a sweep across the silk screen 28. When the porous element 62 is filled with ink, movement of the element across the silk screen forces ink through openings in the screen and on to a blank sheet adjacent the silk screen and thus provide an imprint.

To operate the printing device of FIG. 1 the silk screen with the selected porous sections formed on it to conform to the imprint to be transferred is secured in opening 24 with the frame 12 in its ready position illustrated in FIG. 3. The porous element 62 is filled with ink and then the frame 12 is pivoted downward to lie flat on transparent sheet 22 inits printing position of FIG. 2. This is accomplished manually by the operator pressing against the edge of the frame 12, or by rotational pressure on the handle 56. The handle 56, while pressed down, is moved across the screen 28, thus forcing ink through the porous sections in the silk screen to place a proof imprint on the transparent sheet 22 (illustrated as X Y Z INC in FIG. 1). With this proof imprint on the transparent sheet 22, a blank sheet of paper 66 is placed beneath the transparent sheet 22 to permit the operator to visually align the blank sheet 66 with the imprinted X Y Z INC in a most precise manner. When this is done a suitable guide, for example tape 68, is placed on the upper face of the transparent sheet 22 in line with an edge or edges of the blank sheet 66. The proof imprint is either permitted to dry .or

when ink is needed it is readily applied to the element 62 where it is retained until forced outward through the silk screen by moving it across the frame opening 24. The ink may be applied to the porous element 62 by rocking the cylindrical base 58 in ink, thereby uniformly distributing ink in the element 62. Since base 58 and the element 62 can be positioned either way on the guide rails, it may be turned around to enable maximum use of the ink in the porous element 62. After use, the porous element 62 and base 58 may be readily stored in a jar to keep it from drying out. Thus, it is ready for subsequent use.

This is a highly simplified printing device that enables rapid and straightforward alignment of sheets for multiple imprints. The living hinge biases the frame 12 toward the ready position so that it is easily manipulated and makes for an extremely simplified and economical printing device. In addition, the use of the porous element to retain the ink assures that there will be no possibility of ink spillage as the frame is pivoted between its printing and ready positions. The easel formed by the post 23 and sleeve 21 positively limits the pivoting movement of frame 12 from its printing position. The porous element 62 and base 58 are readily removable from the operator handle 56 so that different ink colors may be easily incorporated with a single handle. The handle and shaft 46 may be readily removed as a unit by twisting handle 56 clockwise or counterclockwise (as viewed in FIG. 1) until the tapered ends 48 of shaft 46 swing out of holes 50, 52 in I the United States is:

1. Printing apparatus comprising:

a base plate upon which a blank sheet is placed for receiving an imprint;

a frame having at least one substantially straight edge and having an opening;

a hinge comprising an elongated relatively thin elastic sheet secured along said edge of the frame andto said base plate whereby said frame is pivotally secured to said base for movement between a printing position in which said frame lies flat on said base and a ready position pivoted away from said base;

'a screen received in said opening, said screen means having porous portions defining a predetermined imprint pattern through which ink can be forced to said blank sheet on said base plate when said frame is in said printing position, thereby causing said blank sheet to receive said imprint; and means for forcing ink through said screen means. 2. Printing apparatus as in claim 1 wherein: the undistorted shape of said hinge is flat and is bent into a shape having a generally U-shaped cross section when said frame is pivoted to said printing position whereby said frame is resiliently biased toward said ready position; and means secured to said base plate to provide a stop for said frame. 3. Printing apparatus as in claim 2 and an inking device comprising:

an operator-manipulated handle; a base removably attached to said handle, said base having a semicylindrical surface, a porous elongated ink-retaining element mounted on the semicylindrical surface of said base, an elongated slot at one end of said handle, a shaft positioned in said slot on an axis transverse to the direction of sweep of said device, and a complementary tab on said base, said tab being releasably retained in said slot 2 and retaining said shaft therein;

first and second guide rails mounted on opposite sides of said opening and positioned parallel to the direction of sweep of said inking device; flexible clips received over said guide rails, each clip having an opening for receiving one of the ends of said shaft.

4. Printing apparatus as in claim 1 wherein said elastic sheet is polypropylene.

5. Printing apparatus as in claim 1 further comprising a resilient transparent sheet lying flat on said base in registry with said opening when said frame is in the I printing position.

i 6. Printing apparatus as in claim 5 wherein said transparent sheet is integral with said elastic sheet. 7. Printing apparatus as in claim 5 further comprising a guide releasably secured to the upper face of said transparent sheet in registration with said proof imprint, thereby permitting successive blank sheets to be positioned on the upper face of said transparent sheet in registration with said proof imprint.

8. Printing apparatus as in claim 6 wherein said guide comprises tape positioned on the upper face of said transparent sheet.

9. Printing apparatus as in claim 1 wherein said means for forcing ink through said screen comprises:

a handle;

a porous ink-retaining element secured to said handle; and

guide means positioned adjacent said opening on said frame for guiding said element in a sweep across said opening.

10. Printing apparatus as in claim 9 wherein:

said handle comprises an operator-manipulated element and a mounting element removably secured to said operator-manipulated element, said mounting element supporting said porous ink-retaining element; and said porous ink-retaining element comprises a flexi ble cellular material.

11.. Printing apparatus as in claim 10 wherein said handle has a shaft with a pair of tapered ends extending transverse to the direction of said sweep, and said guide means comprises first and second guide rails mounted on opposite sides of said opening and positioned parallel to the direction of sweep of said handle;

flexible clips received over said guide rails;

each clip having an opening for receiving one of said tapered ends of said shaft.

12. An inking device for use with a screen printing apparatus having a porous sheet through which ink is forced in a predetermined imprint pattern onto a blank sheet, when said inking device is swept across said porous sheet, said inking device comprising:

an operator-manipulated handle having an elongated slot in one end thereof;

a base removably attached to said handle, said base having a tab complementary to said slot, said tab being releasably retained in said slot, said base having a curved surface; and

a porous elongated ink-retaining element mounted on the curved surface of said base,

the ink in said porous element being forced through said porous sheet as said base and porous element are swept across said porous sheet.

13. An inking device as in claim 12 wherein said curved surface is semi-cylindrical, and wherein a shaft is positioned in said slot on an axis transverse to the direction of sweep of said device, said tab retaining said shaft in said slot.

14. An inking device as in claim 13 wherein said porous elongated element comprises a flexible cellular material. 

1. Printing apparatus comprising: a base plate upon which a blank sheet is placed for receiving an imprint; a frame having at least one substantially straight edge and having an opening; a hinge comprising an elongated relatively thin elastic sheet secured along said edge of the frame and to said base plate whereby said frame is pivotally secured to said base for movement between a printing position in which said frame lies flat on said base and a ready position pivoted away from said base; a screen received in said opening, said screen means having porous portions defining a predetermined imprint pattern through which ink caN be forced to said blank sheet on said base plate when said frame is in said printing position, thereby causing said blank sheet to receive said imprint; and means for forcing ink through said screen means.
 2. Printing apparatus as in claim 1 wherein: the undistorted shape of said hinge is flat and is bent into a shape having a generally U-shaped cross section when said frame is pivoted to said printing position whereby said frame is resiliently biased toward said ready position; and means secured to said base plate to provide a stop for said frame.
 3. Printing apparatus as in claim 2 and an inking device comprising: an operator-manipulated handle; a base removably attached to said handle, said base having a semicylindrical surface, a porous elongated ink-retaining element mounted on the semicylindrical surface of said base, an elongated slot at one end of said handle, a shaft positioned in said slot on an axis transverse to the direction of sweep of said device, and a complementary tab on said base, said tab being releasably retained in said slot and retaining said shaft therein; first and second guide rails mounted on opposite sides of said opening and positioned parallel to the direction of sweep of said inking device; flexible clips received over said guide rails, each clip having an opening for receiving one of the ends of said shaft.
 4. Printing apparatus as in claim 1 wherein said elastic sheet is polypropylene.
 5. Printing apparatus as in claim 1 further comprising a resilient transparent sheet lying flat on said base in registry with said opening when said frame is in the printing position.
 6. Printing apparatus as in claim 5 wherein said transparent sheet is integral with said elastic sheet.
 7. Printing apparatus as in claim 5 further comprising a guide releasably secured to the upper face of said transparent sheet in registration with said proof imprint, thereby permitting successive blank sheets to be positioned on the upper face of said transparent sheet in registration with said proof imprint.
 8. Printing apparatus as in claim 6 wherein said guide comprises tape positioned on the upper face of said transparent sheet.
 9. Printing apparatus as in claim 1 wherein said means for forcing ink through said screen comprises: a handle; a porous ink-retaining element secured to said handle; and guide means positioned adjacent said opening on said frame for guiding said element in a sweep across said opening.
 10. Printing apparatus as in claim 9 wherein: said handle comprises an operator-manipulated element and a mounting element removably secured to said operator-manipulated element, said mounting element supporting said porous ink-retaining element; and said porous ink-retaining element comprises a flexible cellular material.
 11. Printing apparatus as in claim 10 wherein said handle has a shaft with a pair of tapered ends extending transverse to the direction of said sweep, and said guide means comprises: first and second guide rails mounted on opposite sides of said opening and positioned parallel to the direction of sweep of said handle; flexible clips received over said guide rails; each clip having an opening for receiving one of said tapered ends of said shaft.
 12. An inking device for use with a screen printing apparatus having a porous sheet through which ink is forced in a predetermined imprint pattern onto a blank sheet, when said inking device is swept across said porous sheet, said inking device comprising: an operator-manipulated handle having an elongated slot in one end thereof; a base removably attached to said handle, said base having a tab complementary to said slot, said tab being releasably retained in said slot, said base having a curved surface; and a porous elongated ink-retaining element mounted on the curved surface of said base, the ink in said porous element being forced through said porous sheet as saiD base and porous element are swept across said porous sheet.
 13. An inking device as in claim 12 wherein said curved surface is semi-cylindrical, and wherein a shaft is positioned in said slot on an axis transverse to the direction of sweep of said device, said tab retaining said shaft in said slot.
 14. An inking device as in claim 13 wherein said porous elongated element comprises a flexible cellular material. 